BOSTON (CBS) — It was a costly first quarter for the Patriots’ defense in their preseason game against the Titans on Saturday night.

Midway through that first quarter, Derek Rivers rushed off the right edge on a pass play that went for a 20-yard gain. It was unclear what happened to Rivers, but he limped away from the play before going down to the turf. Rivers remained there until the medical staff tended to him. Head coach Bill Belichick walked out to check on Rivers, the defensive end who was drafted in the third round in 2017 but has managed to play in just six over the first two years of his career.

After being looked at in the medical tent, Rivers made his way to the locker room.

Just a few snaps later, Shilique Calhoun rushed off the left edge but got accidentally kicked in the right ankle by teammate Deatrich Wise. Calhoun immediately went down, and after being tended to by the medical staff, he limped to the sideline for further examination.

Calhoun, a linebacker/D-end, was having a strong camp and recorded a solo tackle last week against Detroit.